cc/font_atlas.cc

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "cc/font_atlas.h"
   6
   7 #include <vector>
   8
   9 #include "base/string_split.h"
  10 #include "third_party/skia/include/core/SkCanvas.h"
  11
  12 namespace cc {
  13
  14 FontAtlas::FontAtlas(SkBitmap bitmap, gfx::Rect asciiToRectTable[128], int fontHeight)
  15     : m_atlas(bitmap)
  16     , m_fontHeight(fontHeight)
  17 {
  18     for (size_t i = 0; i < 128; ++i)
  19         m_asciiToRectTable[i] = asciiToRectTable[i];
  20 }
  21
  22 FontAtlas::~FontAtlas()
  23 {
  24 }
  25
  26 void FontAtlas::drawText(SkCanvas* canvas, const SkPaint& paint, const std::string& text, const gfx::Point& destPosition, const gfx::Size& clip) const
  27 {
  28     std::vector<std::string> lines;
  29     base::SplitString(text, '\n', &lines);
  30
  31     gfx::Point position = destPosition;
  32     for (size_t i = 0; i < lines.size(); ++i) {
  33         drawOneLineOfTextInternal(canvas, paint, lines[i], position);
  34         position.set_y(position.y() + m_fontHeight);
  35         if (position.y() > clip.height())
  36             return;
  37     }
  38 }
  39
  40 void FontAtlas::drawOneLineOfTextInternal(SkCanvas* canvas, const SkPaint& paint, const std::string& textLine, const gfx::Point& destPosition) const
  41 {
  42     gfx::Point position = destPosition;
  43     for (unsigned i = 0; i < textLine.length(); ++i) {
  44         // If the ASCII code is out of bounds, then index 0 is used, which is just a plain rectangle glyph.
  45         int asciiIndex = (textLine[i] < 128) ? textLine[i] : 0;
  46         gfx::Rect glyphBounds = m_asciiToRectTable[asciiIndex];
  47         SkIRect source = SkIRect::MakeXYWH(glyphBounds.x(), glyphBounds.y(), glyphBounds.width(), glyphBounds.height());
  48         canvas->drawBitmapRect(m_atlas, &source, SkRect::MakeXYWH(position.x(), position.y(), glyphBounds.width(), glyphBounds.height()), &paint);
  49         position.set_x(position.x() + glyphBounds.width());
  50     }
  51 }
  52
  53 gfx::Size FontAtlas::textSize(const std::string& text)
  54 {
  55     int maxWidth = 0;
  56     std::vector<std::string> lines;
  57     base::SplitString(text, '\n', &lines);
  58
  59     for (size_t i = 0; i < lines.size(); ++i) {
  60         int lineWidth = 0;
  61         for (size_t j = 0; j < lines[i].size(); ++j) {
  62             int asciiIndex = (lines[i][j] < 128) ? lines[i][j] : 0;
  63             lineWidth += m_asciiToRectTable[asciiIndex].width();
  64         }
  65         if (lineWidth > maxWidth)
  66             maxWidth = lineWidth;
  67     }
  68
  69     return gfx::Size(maxWidth, m_fontHeight * lines.size());
  70 }
  71
  72 void FontAtlas::drawDebugAtlas(SkCanvas* canvas, const gfx::Point& destPosition) const
  73 {
  74     SkIRect source = SkIRect::MakeWH(m_atlas.width(), m_atlas.height());
  75     canvas->drawBitmapRect(m_atlas, &source, SkRect::MakeXYWH(destPosition.x(), destPosition.y(), m_atlas.width(), m_atlas.height()));
  76 }
  77
  78 }  // namespace cc